The present invention, in some embodiments thereof, relates to a method of managing transmission parameters in a multi-link wireless transmission network and, more particularly, but not exclusively, to a method of managing transmission frequencies in a multi-link wireless transmission network.
Wireless point-to-point communication systems are often deployed as cellular network backhaul. They usually require a line-of-sight (LOS) and a regulated frequency to ensure high availability throughout the year with little or no interference. A required bit-error-rate in such links is typically below 10−13. Frequency bands commonly used are in the range between 7 GHz and 38 GHz. Higher frequency bands are constantly being proposed and standardized as spectrum resources are scarce.
Since communication in such cases is done as a wireless point-to-point link between two nodes in a network, transmission beams are typically generated using dish antennas which provide some gain and reduce interference. However, narrow beams emitted from dish antennas may still generate interference in other wireless links which use the same frequency, especially when the other links are in a similar direction.
As a rule of thumb, when two wireless links are used for communication with radio beams using same polarization, a different frequency channel is assigned to each of them if the angular separation between them is below 120 degrees. If orthogonal polarizations are used, a 90 degree angular separation is required before different frequency channels are assigned.
Reference is now made to FIG. 1, which is a simplified illustration of angular separation and interference between two wireless communication links in a prior art wireless communication system.
FIG. 1 depicts a first link 101 between two dish antennas 102 103, and a second link 105 between two dish antennas 106 107. An angle 110 is depicted as an angular separation between the two links 101 105.
Transmission from the dish antenna 107 may be received as interference 120 in the dish antenna 102. Transmission from the dish antenna 103 may be received as interference in the dish antenna 106 (not shown). As a matter of fact, transmission from any one of the dish antennas 102 103 106 107 may be received as interference in any one of the other unintended dish antennas 102 103 106 107.
Additional background art includes:
U.S. Pat. No. 8,416,693 to Vanunu et al.
The disclosures of all references mentioned above and throughout the present specification, as well as the disclosures of all references mentioned in those references, are hereby incorporated herein by reference.